NASA symposium on novel ideas for space exploration

When earthlings finally settle on another planet to search for signs of life, Penny Boston knows what they should look for and where, and Berok Khoshnevis how to shelter them in style while they do.

An expert in cave science, Boston has searched for life in extreme environments on Earth for years and said she has the broken bones to prove it. She's an astrobiology professor at the New Mexico Institute of Mining and Technology.

And Khoshnevis, a professor of industrial and systems engineering at the University of Southern California, has developed a radical robotic "contour crafting" process that could rapidly build an entire off-Earth settlement — from landing pads to roads to human habitats — using solar power and in situ materials.

Both are scheduled speakers at the NASA Innovative Advanced Concepts (NIAC) two-day fall symposium in Hampton this week to discuss new and novel technologies to enable space missions over the next century.

"NIAC is the best thing NASA has ever done," Boston said in Wednesday's keynote speech. "It is a place to go with ideas you need to test out on some level, and can't any other way."

'Like two different planets'

If a moon or other planet harbors life — past or present — there's a good chance it's microscopic and located beneath the surface in caves or lava tubes, Boston said. Three-quarters of all life on Earth is microbial.

Microbes thrive even in environments that are inhospitable or lethal to humans, she said. In places that are too hot or too cold, too salty or too acidic. That have too little oxygen or too much carbon monoxide.

"(But for) things that live there," Boston said, "that's their home sweet home."

Extreme Earth environments are templates for planets or moons that might have similar environments, whether on the surface or lurking just beneath. Even on Earth, she said, a hole in the ground is but a "window into the subsurface that can be radically different."

In Saudi Arabia, for instance, she explored a small hole in the desert that belled out into a tremendous underground structure and copious amounts of water.

"The surface and subsurface were like two different planets," Boston said.

Gesturing at photographs of a hole in the lunar surface, she grew wistful.

"I just want to go repel down into that right now," said Boston. "Fly to that moon and jump down. Oh, man, these are juicy, but they also look like death traps, I gotta tell you."

Microbes that thrive in cave environments range from "goo" to red "fluff" to crystalline to mud splatters to "snottites" that Boston said look just like "what comes out of your 2-year-old's nose when he has a cold."

They can be incredibly hardy and tenacious — Boston said they've sequenced the DNA of microbes that were trapped underground for tens of thousands of years. They're still trying to identify one particular microbe that has eluded them for 12 years.

"Even under our feet, we have aliens we can't identify," Boston said.

'You can build anything'

Khoshnevis invented contour crafting a dozen years ago, in part to construct very affordable habitats very quickly for a billion poor and homeless on Earth.

NASA saw its potential for other planets, and offered him a NIAC research fellowship, he said.

It's far too costly to transport building materials or modules off-world — a couple pounds of payload to the moon could run more than $100,000, he said.

"My proposal was just to send the contour crafting machinery, and use the in situ material — the lunar or Martian soil," Khoshnevis explained. "The machinery basically excavates and takes the soil, processes it through the nozzle and builds the structures, one after the other."

The concept is similar to 3D printing, but scaled up. Building designs are limited only by the imagination, he said. All that's required is designing the software, then letting automation do the work.

Lack of water wouldn't be an issue, he said. Mars has plenty of sulfur, which the machines would melt to bind together native sand and gravel. On the moon, machines would melt the soil, itself. They could also extract and process native metals for plumbing and wiring material, then install them.

"It will be self-sufficient," Khoshnevis said. "It can build indefinitely, assuming the machinery are reliable enough."

A lunar settlement would require landing pads to accommodate heavy machinery, and blast walls to protect the settlement from exhaust plumes as landers approach and take off, he said. Then roads stretching between the landing pads and the settlement, and hangars to protect the landers and equipment from solar and cosmic radiation and potential meteorite bombardment.

Depending on how fast NASA wants it, he said, it could all be done in a matter of weeks.

"You give it time," Khoshnevis said, "you can build anything."

The technology is still very new, he said, but in a few years they hope to do a demonstration project in the Arizona desert.

According to program executive Jay Falker, NIAC's slogan is "stretch your imagination … change the possible!"